Additive Concentrate and a Method of Lubricating Transmissions

ABSTRACT

The present invention relates to an additive concentrate comprising a friction modifier, a corrosion inhibitor, and an oil of lubricating viscosity. The invention further provides a method for lubricating a transmission using the additive concentrate.

FIELD OF INVENTION

The present invention relates to an additive concentrate comprising afriction modifier, a corrosion inhibitor, and an oil of lubricatingviscosity. The invention further provides a method for lubricating atransmission using the additive concentrate.

BACKGROUND OF THE INVENTION

Driveline transmissions especially automatic transmission fluids (ATFs),present highly challenging technological problems and solutions forsatisfying the multiple and often conflicting lubricating and powertransmitting requirements of modern automatic transmissions (includingcontinuously variable transmissions of various types). Many additivecomponents are typically included in an ATF, providing such performancecharacteristics as lubrication, dispersancy, friction control (forclutches), antiwear performance, anti-shudder performance,anti-corrosion and anti-oxidation performance. However, over periods ofuse, the additive components are consumed which can detrimentally damagetransmissions. For example a transmission may experience increasedshudder, chattering, or squawking (a vibration oscillation of a clutchthat may be audible). Reducing the impact of shudder, chattering, orsquawking has been achieved by employing friction modifiers such asthose defined in U.S. Pat. Nos. 3,156,653, 3,070,546, 3,275,559, and5,750,476; and U.S. Patent Applications 60/725,360 (now WO 2007/044820),2005/0250655, and 2003/0220208.

U.S. Pat. Nos. 3,156,653; and 3,070,546 both disclose lubricatingcompositions containing a carboxy amide. The lubricating compositionsare suitable for reducing squawking or chattering.

U.S. Pat. No. 3,275,559 discloses an automatic transmission withsuppressed squawking by employing a lubricating composition containingan N-alkyl alkylene diamine.

U.S. Pat. No. 5,750,476 discloses improving anti-shudder durability of apower transmission by employing a lubricating composition containing ananti-shudder improving effective amount of (a) an isomerised alkenylsuccinimide, and (b) an oil-soluble phosphorus-containing compound.

US Patent Application 2003/0220208 discloses a lubricating compositioncontaining an additive combination of (i) an oil-soluble fatty acidester of a polyhydric alcohol and (ii) an oil-soluble fatty acid amide.The lubricating composition is useful for the reduction of brake andclutch noise.

US Patent Application 2005/0250655 discloses a lubricating compositioncontaining a reaction product of a carboxylic acid or a reactiveequivalent thereof with an aminoalcohol, wherein the friction modifiercontains at least two hydrocarbyl groups, each containing at least 6carbon atoms.

U.S. Patent Application 60/725,360 (filed on Oct. 11, 2005, inventorsBartley, Lahiri, Baker and Tipton), now WO 2007/044820, discloses areaction product of a hydroxyalkyl compound with an acylating agent oran amine. The resultant product may be an amide represented by theformula R¹R²N—C(O)R³, wherein R¹ and R² are each independentlyhydrocarbyl groups of at least 6 carbon atoms and R³ is a hydroxyalkylgroup of 1 to 6 carbon atoms or a group formed by the condensation ofsaid hydroxyalkyl group, through a hydroxyl group thereof, with anacylating agent.

Overcoming shudder, chattering, or squawking is typically achieved byreplacing the transmissions' fluid (typically a factory fill fluid) witha replacement fluid. However, this results in excessive repair cost dueto the difficulty of changing the fluid and increased waste lubricant.Thus it would be desirable to lubricate a transmission lubricant capableof minimising noise, shudder, chattering, or squawking, whilst also notadversely affecting the frictional balance and clutch holding capacity,nor increasing lubricant waste. The present invention provides a meansof overcoming shudder, chattering, or squawking whilst at the same timeminimising at least one of the cost, time, and waste involved in aconventional fluid replacement.

SUMMARY OF THE INVENTION

In one embodiment the invention provides an additive concentratecomprising:

-   -   (a) 4 wt % to 67 wt % of a static friction reducing friction        modifier;    -   (b) 0 wt % to 10 wt %, or 0.1 wt % to 5 wt % of a corrosion        inhibitor;    -   (c) 3 wt % to 96 wt % of an oil of lubricating viscosity; and    -   (d) 0 wt % to 20 wt % of other performance additives.

In one embodiment the invention provides a method of lubricating atransmission by supplying to the transmission a lubricating compositionfurther treated with an additive concentrate comprising:

-   -   (a) 4 wt % to 67 wt % of a static friction reducing friction        modifier;    -   (b) 0 wt % to 10 wt %, or 0.1 wt % to 5 wt % of a corrosion        inhibitor;    -   (c) 3 wt % to 96 wt % of an oil of lubricating viscosity; and    -   (d) 0 wt % to 20 wt % of other performance additives.

In one embodiment the invention provides a method of lubricating atransmission containing a lubricant comprising supplying to thelubricant within the transmission an additive concentrate comprising:

-   -   (a) 4 wt % to 67 wt % of a static friction reducing friction        modifier;    -   (b) 0 wt % to 10 wt %, or 0.1 wt % to 5 wt % of a corrosion        inhibitor;    -   (c) 3 wt % to 96 wt % of an oil of lubricating viscosity; and    -   (d) 0 wt % to 20 wt % of other performance additives.

In one embodiment the invention provides an additive concentratecomprising:

-   -   (a) 4 wt % to 67 wt % of a friction modifier with a co-efficient        of friction of greater than 0.09;    -   (b) 0 wt % to 10 wt %, or 0.1 wt % to 5 wt % of a corrosion        inhibitor;    -   (c) 3 wt % to 96 wt % of an oil of lubricating viscosity; and    -   (d) 0 wt % to 20 wt % of other performance additives.

In one embodiment the invention provides a method of lubricating atransmission by supplying to the transmission a lubricating compositionfurther treated with an additive concentrate comprising:

-   -   (a) 4 wt % to 67 wt % of a friction modifier with a co-efficient        of friction of greater than 0.09;    -   (b) 0 wt % to 10 wt %, or 0.1 wt % to 5 wt % of a corrosion        inhibitor;    -   (c) 3 wt % to 96 wt % of an oil of lubricating viscosity; and    -   (d) 0 wt % to 20 wt % of other performance additives.

In one embodiment the invention provides a method of lubricating atransmission containing a lubricant comprising supplying to thelubricant within the transmission an additive concentrate comprising:

-   -   (a) 4 wt % to 67 wt % of a friction modifier with a co-efficient        of friction of greater than 0.09;    -   (b) 0 wt % to 10 wt %, or 0.1 wt % to 5 wt % of a corrosion        inhibitor;    -   (c) 3 wt % to 96 wt % of an oil of lubricating viscosity; and    -   (d) 0 wt % to 20 wt % of other performance additives.

In one embodiment the invention provides for the use of the additiveconcentrate described herein as a top treat package to diminish squawkin a transmission.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides an additive concentrate and a method forlubricating a transmission as disclosed above.

The additive concentrate is typically added as a top treat. The toptreat may be added to the transmission as a service-fill orfactory-fill. Typically the top treat may be added to the transmissionas a service-fill.

The additive concentrate may contain the static friction reducingfriction modifier at 4 wt % to 67 wt %, or 10 wt % to 50 wt %, or 20 wt% to 40 wt %.

The additive concentrate may contain the corrosion inhibitor at 0 wt %to 10 wt %, or 0.1 wt % to 5 wt %, or 0.2 wt % to 3 wt %.

The additive concentrate may contain the oil of lubricating viscosity at3 wt % to 96 wt %, or 33 wt % to 89 wt %, or 47 wt % to 77.8 wt %.

The additive concentrate may contain the total of other performanceadditives at 0 wt % to 20 wt %, or 1 wt % to 12 wt %, or 2 wt % to 10 wt%.

The additive concentrate may be added to a transmission at a treat rateof 0.1 wt % to 30 wt %, or 1 wt % to 15 wt %.

Static Friction Reducing Friction Modifiers

The static friction reducing friction modifier may also be described asa friction modifier with a co-efficient of friction of greater than0.09. The static friction is expressed in term of μT or the stabilizedstatic coefficient from the SAE#2 test procedure. The test procedure isdescribed in the Japanese Automobile Standard, JASO M-348-95, “Testmethod for friction property of automatic transmission fluids”.

The static friction reducing friction modifier may also be described asa friction modifier of the type described in PCT Publication WO2004/007652 A1. Typically static friction reducing friction modifiersare characterised by their ability to provide a positive slope in afriction versus speed curve whilst maintaining a high static coefficientof friction.

In one embodiment the static friction reducing friction modifier may beformed by the condensation of the hydroxyalkyl compound with anacylating agent or an amine. A more detailed description of thehydroxyalkyl compound is described in U.S. Patent Application 60/725,360(filed on Oct. 11, 2005, inventors Bartley, Lahiri, Baker and Tipton) inparagraphs 8, and 19-21, now WO 2007/044820. The friction modifierdisclosed in U.S. Patent Application 60/725,360 may be an amiderepresented by the formula R¹R²N—C(O)R³, wherein R¹ and R² are eachindependently hydrocarbyl groups of at least 6 carbon atoms and R³ is ahydroxyalkyl group of 1 to 6 carbon atoms or a group formed by thecondensation of said hydroxyalkyl group, through a hydroxyl groupthereof, with an acylating agent. Preparative Examples are disclosed inExamples 1 and 2 (paragraphs 68 and 69 of U.S. Patent Application60/725,360). In one embodiment the amide of a hydroxylalkyl compound isprepared by reacting glycolic acid, that is, hydroxyacetic acid,HO—CH₂—COOH with an amine.

In one embodiment the static friction reducing friction modifier may bederived from the reaction product of a carboxylic acid or a reactiveequivalent thereof with an aminoalcohol, wherein the friction modifiercontains at least two hydrocarbyl groups, each containing at least 6carbon atoms. The number of carbon atoms may range from 6 to 30, or 8 to20. An example of such a friction modifier includes the reaction productof isostearic acid or an alkyl succinic anhydride withtris-hydroxymethylaminomethane. A more detailed description of such afriction modifier is disclosed in US Patent Application 2003/22000 (orInternational Publication WO04/007652) in paragraphs 8 and 9 to 14.

In one embodiment the static friction reducing friction modifier may bea polyol ester as described in U.S. Pat. No. 5,750,476 column 8, line 40to column 9, line 28.

In one embodiment the static friction reducing friction modifier may bea low potency friction modifier as described in U.S. Pat. No. 5,840,662in column 2, line 28 to column 3, line 26. U.S. Pat. No. 5,840,662further discloses in column 3, line 48 to column 6, line 25 specificmaterials and methods of preparing the low potency friction modifier.

In one embodiment the friction modifier may be a hydroxylamine compoundas defined in column 37, line 19, to column 39, line 38 of U.S. Pat. No.5,534,170. Optionally the hydroxylamine may be borated as such productsare described in column 39, line 39 to column 40 line 8 of U.S. Pat. No.5,534,170.

In one embodiment the static friction reducing friction modifiercomprises one or more of a hydroxy-amide, a hydroxy amide mono- ordi-ester, a hydroxy oxazoline, a hydroxy oxazoline ester, an oxazolinediester, a tri-ester amide, or mixtures thereof.

In one embodiment the static friction reducing modifier is an amiderepresented by the formula R¹R²N—C(O)R³, wherein R¹ and R² are eachindependently hydrocarbyl groups of at least 6 carbon atoms and R³ is ahydroxyalkyl group of 1 to 6 carbon atoms or a group formed by thecondensation of said hydroxyalkyl group, through a hydroxyl groupthereof, with an acylating agent.

In one embodiment the static friction reducing modifier is other than anamide represented by the formula R¹, R²N—C(O)R³, wherein R¹ and R² areeach independently hydrocarbyl groups of at least 6 carbon atoms and R³is a hydroxyalkyl group of 1 to 6 carbon atoms or a group formed by thecondensation of said hydroxyalkyl group, through a hydroxyl groupthereof, with an acylating agent.

In one embodiment the static friction reducing modifier is a tertiaryamine. The amine will contain three substituent hydrocarbyl groups, twoof which are alkyl groups. The amine is represented by the formula

R⁴R⁵NR⁶

wherein R⁴ and R⁵ are each independently an alkyl group of at least 6carbon atoms (e.g., 8 to 20 carbon atoms or 10 to 18 or 12 to 16) and R⁶is a polyhydroxyl-containing alkyl group or a polyhydroxyl-containingalkoxyalkyl group.

In one embodiment the amine comprises a product of di-cocoalkyl amine orhomologous amines. Di-cocoalkyl amine (or di-cocoamine) is a secondaryamine in which two of the R groups in the above formula arepredominantly C₁₂ groups, derived from coconut oil and the remaining Rgroup is H.

In one embodiment, R⁶ is a polyol-containing alkyl group (that is, agroup containing 2 or more hydroxy groups) or a group containing one ormore hydroxy groups and one or more amine groups. For instance, R⁶ maybe —CH₂—CHOH—CH₂OH or a homologue thereof, containing, for example, 3 to8 carbon atoms or 3 to 6 carbon atoms or 3 to 4 carbon atoms, and 2, 3,4 or more hydroxy groups (normally no more than one hydroxy group percarbon atom). A typical resulting product may thus be represented by

R⁴R⁵N—CH₂—CHOH—CH₂OH

-   -   or homologues thereof, where R⁴ and R⁵ are, as described above,        independently alkyl groups of 8 to 20 carbon atoms. Such        products may be obtained by the reaction of a dialkyl amine with        an epoxide or chlorohydroxy compound. In particular, reaction of        a secondary amine with glycidol (2,3-epoxy-1-propanol) or        “chloroglycerine” (that is, 3-chloropropane-1,2-diol) may be        effective under conditions as described above. Such materials        based on the reaction of dicocoamine with one or more moles of        glycidol or chloroglycerine are particularly useful in providing        friction-modifying performance. If reaction is with multiple        moles of glycidol or chloroglycerine, or other epoxyalkanols or        chlorodiols, a dimeric or oligomeric ether-containing group,        that is, a hydroxyl-substituted alkoxyalkyl group, may result.

In one embodiment the static friction reducing modifier may be describedas a compound comprising a core portion comprising 3 to 8 carbon atoms,(e.g., 3 to 6, or 3 carbon atoms), said core portion being substitutedby:

(i) at least two hydroxy groups, or at least one hydroxy group and atleast one alkoxy group of 1 to 4 carbon atoms wherein said alkoxy groupis further substituted by at least one hydroxy group or another suchalkoxy group; and(ii) at least one amino group, the nitrogen atom thereof bearing twohydrocarbyl groups, each such hydrocarbyl group independently having 6to 30 carbon atoms.

In one embodiment the static friction reducing modifier is a secondaryor tertiary amine. The amine will contain at least two substituenthydrocarbyl groups, for example, alkyl groups. The amine is representedby the formula

R⁷R⁸NR⁹

wherein R⁷ and R⁸ are each independently an alkyl group of at least 6carbon atoms (e.g., 8 to 20 carbon atoms or 10 to 18 or 12 to 16) and R⁹is a hydroxyl-containing alkyl group, a hydroxyl-containing alkoxyalkylgroup, an amine-containing alkyl group, a hydrocarbyl group, orhydrogen, provided that when R⁹ is H, then at least one of R⁷ and R⁸ isan alkyl group of 8 to 16 carbon atoms such as, for instance, 10 to 16carbon atoms or 12 to 14 carbon atoms. In certain embodiments both of R⁷and R⁸ are alkyl groups of 8 to 16, or 10 to 16, or 12 to 14 carbonatoms. A commercial example of such an amine is Armeen 2C™, which is asecondary amine where the two alkyl groups are believed to bepredominately C₁₂ to C₁₄.

In one embodiment the amine comprises di-cocoalkyl amine or homologousamines. Di-cocoalkyl amine (or di-cocoamine) is a secondary amine inwhich two of the R groups in the above formula are predominantly C₁₂groups, derived from coconut oil and the remaining R group is H. Inanother embodiment the amine may be Armeen HTL8™, which is believed tobe a secondary amine with mixed alkyl groups comprising 2-ethylhexylgroups (C8) and hydrogenated tallow groups (largely C16-18).

In another embodiment, R⁹ in the above structure is —CH₂—CHOH—R¹⁰, whereR¹⁰ is hydrogen or an alkyl group, e.g., a methyl group or an alkylgroup of 1 to 26 carbon atoms, or 6 to 20 carbon atoms, or 12 to 18carbon atoms, or 14 to 16 carbon atoms, or 14 carbon atoms. Suchmaterials can be prepared by reaction of a secondary amine such asdi-cocoalkylamine with an epoxide, such as propylene oxide (in the casewhere R¹⁰ is methyl). The resulting products can thus, morespecifically, be represented by the structure

R⁷R⁸N—CH₂—CHOH—CH₃

where R⁷ and R⁸ are, as described above, independently alkyl groups of 8to 20 carbon atoms. The reaction of the dialkyl amine and the epoxidecan be effected by reaction under pressure in the presence of a basiccatalyst. In another embodiment, R⁹ is an aminopropyl groups such as—CH₂—CH₂—CH₂—NH₂, and the resulting product can be prepared by reactionof a secondary amine such as dicocoalkyl amine with acrylonitrilefollowed by a reduction.

In another embodiment, R⁹ can be a polyol-containing alkyl group (thatis, a group containing 2 or more hydroxy groups) or a group containingone or more hydroxy groups and one or more amine groups. For instance,R⁹ may be —CH₂—CHOH—CH₂OH or a homologue thereof, containing, forexample, 3 to 8 carbon atoms or 3 to 6 carbon atoms or 3 to 4 carbonatoms, and 2, 3, 4 or more hydroxy groups (normally no more than onehydroxy group per carbon atom). A typical resulting product may thus berepresented by

R⁷R⁸N—CH₂—CHOH—CH₂OH

or homologues thereof, where R⁷ and R⁸ are, as described above,independently alkyl groups of 8 to 20 carbon atoms. Such products may beobtained by the reaction of a dialkyl amine with an epoxide orchlorohydroxy compound. In particular, reaction of a secondary aminewith glycidol (2,3-epoxy-1-propanol) or “chloroglycerine” (that is,3-chloropropane-1,2-diol) may be effective under conditions as describedabove. Such materials based on the reaction of dicocoamine with one ormore moles of glycidol or chloroglycerine are particularly useful inproviding friction-modifying performance. If reaction is with multiplemoles of glycidol or chloroglycerine, or other epoxyalkanols orchlorodiols, a dimeric or oligomeric ether-containing group, that is, ahydroxyl-substituted alkoxyalkyl group, may result.

In certain embodiments, thus, the amine may be a tertiary amine, thatis, in which R⁹ is other than hydrogen. If all three groups R⁷, R⁸, andR⁹ are alkyl groups, then R⁹ may also be an alkyl group of at least 6carbon atoms (e.g., 8 to 20 carbon atoms or 10 to 18 or 12 to 16).

Corrosion Inhibitor

The lubricating composition may further comprise a corrosion inhibitoror mixtures thereof. In one embodiment the corrosion inhibitor alsoexhibits antiwear properties.

The corrosion inhibitors of the invention include benzotriazoles(typically tolyltriazole), 2-alkyldithiobenzimidazoles or 2-alkyldithiobenzothiazoles, 1,2,4-triazoles, benzimidazoles, octylamine octanoate,condensation products of dodecenyl succinic acid or anhydride,dimercaptothiadiazoles and reactive equivalents thereof, or mixturesthereof.

The corrosion inhibitor may comprise at least one of adimercaptothiadiazole, 5-dimercapto-[1,3,4]-thiadiazole,3,5-dimercapto-[1,2,4]-thiadiazole, 3,4-dimercapto-[1,2,5]-thiadiazole,or 4-5-dimercapto-[1,2,3]-thiadaizole. Typically readily availablematerials such as 2,5-dimercapto-1,3-4-thiadiazole or ahydrocarbyl-substituted 2,5-dimercapto-1,3-4-thiadiazole are commonlyutilised, with 2,5-dimercapto-[1,3,4]-thiadiazole most commonly utiliseddue to availability. In several embodiments the number of carbon atomson the hydrocarbyl-substituent group includes 1 to 30, 2 to 25, 4 to 20,6 to 16, or 8 to 10.

In one embodiment, the thiazole compound may be the reaction product ofa phenol with an aldehyde and a dimercaptothiadiazole. The phenol may bean alkyl phenol wherein the alkyl group contains at least about 6, e.g.,6 to 24, or 6, or 7, to 12 carbon atoms. The aldehyde may be an aldehydecontaining 1 to 7 carbon atoms or an aldehyde synthon, such asformaldehyde. In one embodiment, the aldehyde is formaldehyde orparaformaldehyde. The aldehyde, phenol and dimercaptothiadiazole aretypically reacted by mixing them at a temperature up to about 150° C.such as 50° C. to 130° C., in molar ratios of 0.5 to 2 moles of phenoland 0.5 to 2 moles of aldehyde per mole of dimercaptothiadiazole. In oneembodiment, the three reagents are reacted in equal molar amounts. Theproduct may be described as an alkylhydroxyphenylmethylthio-substituted[1,3,4]-thiadiazole; the alkyl moiety may be, among others, hexyl,heptyl, octyl, or nonyl.

Useful thiadiazole compounds thus may include2-alkyldithio-5-mercapto-[1,3,4]-thiadiazoles,2,5-bis(alkyldithio)-[1,3,4]-thiadiazoles,2-alkylhydroxyphenylmethylthio-5-mercapto-[1,3,4]-thiadiazoles, andmixtures thereof.

Examples of suitable thiadiazole compounds include2-octyldithio-5-mercapto-1,3,4-thiadiazole,2-nonyldithio-5-mercapto-1,3,4-thiadiazole,2-dodecydithio-5-mercapto-1,3,4-thiadiazole,2,5-dimercapto-1,3-4-thiadiazole (e.g.,2,5-bis(alkyl-dithio)-1,3,4-thiadiazoles) include2,5-bis(tert-octyldithio)-1,3,4-thiadiazole2,5-bis(tert-nonyldithio)-1,3,4-thiadiazole,2,5-bis(tert-decyldithio)-1,3,4-thiadiazole,2,5-bis(tert-undecyldithio)-1,3,4-thiadiazole,2,5-bis(tert-dodecyldithio)-1,3,4-thiadiazole,2,5-bis(tert-tridecyldithio)-1,3,4-thiadiazole,2,5-bis(tert-tetradecyldithio)-1,3,4-thiadiazole,2,5-bis(tert-pentadecyldithio)-1,3,4-thiadiazole,2,5-bis(tert-hexadecyldithio)-1,3,4-thiadiazole,2,5-bis(tert-heptadecyldithio)-1,3,4-thiadiazole,2,5-bis(tert-octadecyldithio)-1,3,4-thiadiazole,2,5-bis(tert-nonadecyldithio)-1,3,4-thiadiazole or2,5-bis(tert-eicosyldithio)-1,3,4-thiadiazole, or oligomers thereof. Inone embodiment the hydrocarbyl-substituted2,5-dimercapto-1,3-4-thiadiazole comprises at least one of2,5-bis(tert-octyldithio)-1,3,4-thiadiazole2,5-bis(tert-nonyldithio)-1,3,4-thiadiazole, or2,5-bis(tert-decyldithio)-1,3,4-thiadiazole.

Oils of Lubricating Viscosity

The lubricating composition comprises an oil of lubricating viscosity.Such oils include natural and synthetic oils, oil derived fromhydrocracking, hydrogenation, and hydrofinishing, unrefined, refined andre-refined oils and mixtures thereof.

Unrefined oils are those obtained directly from a natural or syntheticsource generally without (or with little) further purificationtreatment.

Refined oils are similar to the unrefined oils except they have beenfurther treated in one or more purification steps to improve one or moreproperties. Purification techniques are known in the art and includesolvent extraction, secondary distillation, acid or base extraction,filtration, and percolation.

Re-refined oils are also known as reclaimed or reprocessed oils, and areobtained by processes similar to those used to obtain refined oils andoften are additionally processed by techniques directed to removal ofspent additives and oil breakdown products.

Natural oils useful in making the inventive lubricants include animaloils (e.g., lard oil), vegetable oils (e.g., castor oil), minerallubricating oils such as liquid petroleum oils and solvent-treated oracid-treated mineral lubricating oils of the paraffinic, naphthenic ormixed paraffinic-naphthenic types and oils derived from coal or shale ormixtures thereof.

Synthetic lubricating oils are useful and include hydrocarbon oils suchas polymerised and interpolymerised olefins (e.g., polybutylenes,polypropylenes, propyleneisobutylene copolymers); poly(1-hexenes),poly(1-octenes), poly(1-decenes), and mixtures thereof; alkyl-benzenes(e.g. dodecylbenzenes, tetradecylbenzenes, dinonylbenzenes,di-(2-ethylhexyl)-benzenes); polyphenyls (e.g., biphenyls, terphenyls,alkylated polyphenyls); alkylated diphenyl ethers and alkylated diphenylsulphides and the derivatives, analogs and homologs thereof or mixturesthereof.

Other synthetic lubricating oils include polyol esters (such asProlube®3970), diesters, liquid esters of phosphorus-containing acids(e.g., tricresyl phosphate, trioctyl phosphate, and the diethyl ester ofdecane phosphonic acid), or polymeric tetrahydrofurans. Synthetic oilsmay be produced by Fischer-Tropsch reactions and typically may behydroisomerised Fischer-Tropsch hydrocarbons or waxes. In oneembodiment, oils may be prepared by a Fischer-Tropsch gas-to-liquidsynthetic procedure as well as other gas-to-liquid oils.

Oils of lubricating viscosity may also be defined as specified in theAmerican Petroleum Institute (API) Base Oil InterchangeabilityGuidelines. The five base oil groups are as follows: Group I (sulphurcontent >0.03 wt %, and/or <90 wt % saturates, viscosity index 80-120);Group II (sulphur content ≦0.03 wt %, and ≧90 wt % saturates, viscosityindex 80-120); Group III (sulphur content ≦0.03 wt %, and ≧90 wt %saturates, viscosity index ≧120); Group IV (all polyalphaolefins(PAOs)); and Group V (all others not included in Groups I, II, III, orIV). The oil of lubricating viscosity comprises an API Group I, GroupII, Group III, Group IV, Group V oil or mixtures thereof. In oneembodiment the oil of lubricating viscosity may be an API Group I, GroupII, Group III, Group IV oil or mixtures thereof. In one embodiment theoil of lubricating viscosity may be an API Group II, Group III or GroupIV oil or mixtures thereof. In one embodiment the oil of lubricatingviscosity may be an API Group II or Group III oil or mixtures thereof.

In one embodiment the oil of lubricating viscosity is other than a whiteoil base stock.

The amount of the oil of lubricating viscosity present is typically thebalance remaining after subtracting from 100 wt % the sum of the staticfriction reducing friction modifier, the corrosion inhibitor and theother performance additives (described below).

The lubricating composition may be in the form of a concentrate and/or afully formulated lubricant. If the composition is in the form of aconcentrate (which may be combined with additional oil to form, in wholeor in part, a finished lubricant), the ratio of the of components (a),(b) and (d) to the oil of lubricating viscosity (c) and/or to diluentoil include the ranges of 1:99 to 99:1 by weight, or 80:20 to 10:90 byweight.

Other Performance Additive

The composition of the invention optionally further includes at leastone other performance additive. The other performance additives includedetergents, viscosity index improvers (also referred to as viscositymodifiers), antiwear agents, friction modifiers other than the staticreducing friction modifier of the invention, friction stabilisingagents, antioxidants, dispersants, foam inhibitors, demulsifiers, pourpoint depressants, seal swelling agents and mixtures thereof.

Antiwear Agent

The antiwear agent may be a phosphorus-containing acid, salt, or ester,or mixtures thereof.

The antiwear agent may be metal-containing or metal free (prior to beingmixed with other components).

The antiwear agent may be derived from a phosphoric acid, phosphorousacid, thiophosphoric acid, thiophosphorous acid, or mixtures thereof.

The antiwear agent may include (i) a non-ionic phosphorus compound; (ii)an amine salt of a phosphorus compound; (iii) an ammonium salt of aphosphorus compound; (iv) a monovalent metal salt of a phosphoruscompound, such as a metal dialkyldithiophosphate or a metaldialkylphosphate; or (v) mixtures of (i), (ii), (iii) or (iv).

In one embodiment the antiwear agent comprises a metaldialkyldithiophosphate or a metal dialkylphosphate. The alkyl groups ofthe dialkyldithiophosphate and/or the dialkylphosphate may be linear orbranched containing 2 to 20 carbon atoms, provided that the total numberof carbons is sufficient to make the metal dialkyldithiophosphate or-phosphate oil soluble. The metal of the metal dialkyldithiophosphateand/or dialkylphosphate typically includes monovalent or divalentmetals. Examples of suitable metals include sodium, potassium, copper,calcium, magnesium, barium or zinc. In one embodiment the antiwear agentis a zinc dialkyldithiophosphate. In one embodiment the antiwear agentis a zinc dialkylphosphate.

Examples of a suitable zinc dialkyldithiophosphate (often referred to asZDDP, ZDP or ZDTP) include zinc di-(amyl)dithiophosphate, zincdi-(1,3-dimethylbutyl)dithiophosphate, zinc di-(heptyl)dithiophosphate,zinc di-(octyl)dithiophosphate di-(2-ethylhexyl)dithiophosphate, zincdi-(nonyl)dithiophosphate, zinc di-(decyl)dithiophosphate, zincdi-(dodecyl)dithiophosphate, zinc di-(dodecylphenyl)dithiophosphate,zinc di-(heptylphenyl)dithiophosphate, or mixtures thereof. In oneembodiment the zinc dialkyldithiophosphate comprises a mixed alkyl ZDDPcompound, wherein the alkyl groups include 2-methylpropyl and amyl. Inone embodiment the zinc dialkyldithiophosphate comprises a mixed alkylZDDP compound, wherein one alkyl group comprises isopropyl and at leastone of 1,3-dimethylbutyl, 2-ethylhexyl and iso-octyl.

In one embodiment the antiwear agent is other than metaldialkyldithiophosphate.

In one embodiment the antiwear agent comprises an ammonium or amine saltof a phosphorus-containing acid or ester.

The amine salt of a phosphorus acid or ester includes phosphoric acidesters and amine salts thereof; dialkyldithiophosphoric acid esters andamine salts thereof; amine salts of phosphites; and amine salts ofphosphorus-containing carboxylic esters, ethers, and amides; andmixtures thereof.

The amine salt of a phosphorus acid or ester may be used alone or incombination. In one embodiment the amine salt of a phosphorus compoundis derived from an amine salt of a phosphorus compound, or mixturesthereof.

In one embodiment the amine salt of a phosphorus acid or ester includesa partial amine salt-partial metal salt compounds or mixtures thereof.In one embodiment the amine salt of a phosphorus acid or ester furthercomprises a sulphur atom in the molecule.

The amines which may be suitable for use as the amine salt includeprimary amines, secondary amines, tertiary amines, and mixtures thereof.The amines include those with at least one hydrocarbyl group, or, incertain embodiments, two or three hydrocarbyl groups. The hydrocarbylgroups may contain 2 to 30 carbon atoms, or in other embodiments 8 to26, or 10 to 20, or 13 to 19 carbon atoms.

Primary amines include ethylamine, propylamine, butylamine,2-ethylhexylamine, octylamine, and dodecylamine, as well as such fattyamines as n-octylamine, n-decylamine, n-dodecylamine, n-tetradecylamine,n-hexadecylamine, n-octadecylamine and oleyamine. Other useful fattyamines include commercially available fatty amines such as “Armeen®”amines (products available from Akzo Chemicals, Chicago, Ill.), such asArmeen C, Armeen O, Armeen O L, Armeen T, Armeen H T, Armeen S andArmeen S D, wherein the letter designation relates to the fatty group,such as coco, oleyl, tallow, or stearyl groups.

Examples of suitable secondary amines include dimethylamine,diethylamine, dipropylamine, dibutylamine, diamylamine, dihexylamine,diheptylamine, methylethylamine, ethylbutylamine, di-cocoalkyl amine (ordi-cocoamine) and ethylamylamine. The secondary amines may be cyclicamines such as piperidine, piperazine and morpholine.

The amine may also be a tertiary-aliphatic primary amine. The aliphaticgroup in this case may be an alkyl group containing 2 to 30, or 6 to 26,or 8 to 24 carbon atoms. Tertiary alkyl amines include monoamines suchas tert-butylamine, tert-hexylamine, 1-methyl-1-amino-cyclohexane,tert-octylamine, tert-decylamine, tertdodecylamine,tert-tetradecylamine, tert-hexadecylamine, tert-octadecylamine,tert-tetracosanylamine, and tert-octacosanylamine.

In one embodiment the amine salt of a phosphorus acid or ester includesan amine with C11 to C14 tertiary alkyl primary groups or mixturesthereof. In one embodiment the amine salt of a phosphorus compoundincludes an amine with C14 to C18 tertiary alkyl primary amines ormixtures thereof. In one embodiment the amine salt of a phosphoruscompound includes an amine with C18 to C22 tertiary alkyl primary aminesor mixtures thereof.

Mixtures of amines may also be used in the invention. In one embodimenta useful mixture of amines is “Primene® 81R” and “Primene® JMT.”Primene® 81R and Primene® JMT (both produced and sold by Rohm & Haas)are mixtures of C11 to C14 tertiary alkyl primary amines and C18 to C22tertiary alkyl primary amines respectively.

In one embodiment the amine salt of a phosphorus acid or ester is thereaction product of a C₁₄ to C₁₈ alkylated phosphoric acid with Primene81R™ (produced and sold by Rohm & Haas) which is a mixture of C11 to C14tertiary alkyl primary amines.

Examples of the amine salt of a phosphorus acid or ester include thereaction product(s) of isopropyl, methyl-amyl (1,3-dimethylbutyl ormixtures thereof), 2-ethylhexyl, heptyl, octyl or nonyl dithiophosphoricacids with ethylene diamine, morpholine, or Primene 81R™, and mixturesthereof.

In one embodiment a dithiophosphoric acid may be reacted with an epoxideor a glycol. This reaction product is further reacted with a phosphorusacid, anhydride, or lower ester (where “lower” signifies 1 to 8, or 1 to6, or 1 to 4, or 1 to 2 carbon atoms in the alcohol-derived portion ofthe ester). The epoxide includes an aliphatic epoxide or a styreneoxide. Examples of useful epoxides include ethylene oxide, propyleneoxide, butene oxide, octene oxide, dodecene oxide, styrene oxide and thelike. In one embodiment the epoxide is propylene oxide. The glycols maybe aliphatic glycols having 1 to 12, or 2 to 6, or 2 to 3 carbon atoms.The dithiophosphoric acids, glycols, epoxides, inorganic phosphorusreagents and methods of reacting the same are described in U.S. Pat.Nos. 3,197,405 and 3,544,465. The resulting acids may then be saltedwith amines. An example of suitable dithiophosphoric acid is prepared byadding phosphorus pentoxide (about 64 grams) at 58° C. over a period of45 minutes to 514 grams of hydroxypropylO,O-di(1,3-dimethylbutyl)phosphorodithioate (prepared by reactingdi(1,3-dimethylbutyl)-phosphorodithioic acid with 1.3 moles of propyleneoxide at 25° C.). The mixture is heated at 75° C. for 2.5 hours, mixedwith a diatomaceous earth and filtered at 70° C. The filtrate contains11.8% by weight phosphorus, 15.2% by weight sulphur, and an acid numberof 87 (bromophenol blue).

In one embodiment the antiwear agent comprises a non-ionic phosphoruscompound. Typically the non-ionic phosphorus compound may have anoxidation of +3 or +5. The different embodiments comprise phosphiteester, phosphate esters, or mixtures thereof.

In one embodiment the antiwear agent comprises a non-ionic phosphoruscompound that is a hydrocarbyl phosphite. The hydrocarbyl phosphite ofthe invention includes those represented by the formula:

wherein each R′″ may be independently hydrogen or a hydrocarbyl group,with the proviso that at least one of the R′″ groups is hydrocarbyl.

Each hydrocarbyl group of R′″ may contain at least 2 or 4 carbon atoms.Typically, the combined total sum of carbon atoms present on both R′″groups may be less than 45, less than 35 or less than 25. Examples ofsuitable ranges for the number of carbon atoms present on both R″ groupsincludes 2 to 40, 3 to 24 or 4 to 20. Examples of suitable hydrocarbylgroups include propyl, butyl, pentyl, hexyl dodecyl, butadecyl,hexadecyl, or octadecyl groups. Generally the hydrocarbyl phosphite issoluble or at least dispersible in oil. In one embodiment thehydrocarbyl phosphite may be di-butyl hydrogen phosphite or a C₁₆₋₁₈alkyl hydrogen phosphite. A more detailed description of the non-ionicphosphorus compound is found in column 9, line 48 to column 11, line 8of U.S. Pat. No. 6,103,673.

Other Friction Modifiers

Another friction modifier (i.e. other than component (a) of theinvention) may be present, including fatty amines, borated glycerolesters, fatty acid amides, non-borated fatty epoxides, borated fattyepoxides, alkoxylated fatty amines, borated alkoxylated fatty amines,metal salts of fatty acids, fatty imidazolines, metal salts of alkylsalicylates, condensation products of carboxylic acids orpolyalkylene-polyamines, or amides of hydroxyalkyl compounds.

In one embodiment the other friction modifier may include a fatty acidester of glycerol. The final product may be in the form of a metal salt,an amide, an imidazoline, or mixtures thereof. The fatty acids maycontain 6 to 24 or 8 to 18 carbon atoms. The fatty acids may branched orstraight-chain, saturated or unsaturated. Suitable acids include2-ethylhexanoic, decanoic, oleic, stearic, isostearic, palmitic,myristic, palmitoleic, linoleic, lauric, and linolenic acids, and theacids from the natural products tallow, palm oil, olive oil, peanut oil,corn oil, and Neat's foot oil. In one embodiment the fatty acid is oleicacid.

When in the form of a metal salt, typically the metal may be zinc orcalcium and the products may be overbased. Examples are overbasedcalcium salts and basic oleic acid-zinc salt complexes. The zinc saltmay be acidic, neutral or basic (overbased). These salts may be preparedfrom the reaction of a zinc containing reagent with a carboxylic acid orsalt thereof. A useful method of preparation of these salts is to reactzinc oxide with a carboxylic acid. Useful carboxylic acids includecarboxylic acids of the formula R¹COOH where R¹ is an aliphatic oralicyclic hydrocarbon radical. In one embodiment R¹ is a fatty groupsuch as stearyl, oleyl, linoleyl, palmityl, or mixtures thereof. In oneembodiment the zinc salt contains stoichiometric excess of zinc over theamount needed to prepare a neutral salt. The stoichiometry includes zincpresent from 1.1 to 1.8 times the stoichiometric, or 1.3 to 1.6 timesthe stoichiometric amount of zinc. The zinc carboxylates are known inthe art and are described in U.S. Pat. No. 3,367,869. Metal salts mayalso include calcium salts. Examples may include overbased calciumsalts.

When in the form of an amide, the condensation product may be preparedwith ammonia, or with primary or secondary amines such as diethylamineand diethanolamine.

When in the form of an imidazoline, the cyclic condensation product of afatty acid ester of glycerol with a diamine or polyamine such as apolyethylenepolyamine. In one embodiment the other friction modifier isthe condensation product of a C8 to C24 fatty acid with a polyalkylenepolyamine, and in particular, the product of isostearic acid withtetraethylenepentamine.

In one embodiment the other friction modifier may be an alkoxylatedalcohol. A detailed description of suitable alkyoxylated alcohols isdescribed in paragraphs 19 and 20 of US Patent Application 2005/0101497.The alkoxylated amines are also described in U.S. Pat. No. 5,641,732 incolumn 7, line 15 to column 9, line 25.

In one embodiment the other friction modifier may be an alkoxylatedamine e.g., an ethoxylated amine derived from 1.79% Ethomeen T-12 and0.90% Tomah PA-1 as described in Example E of U.S. Pat. No. 5,703,023,column 28, lines 30 to 46. Other suitable alkoxylated amine compoundsinclude commercial alkoxylated fatty amines known by the trademark“ETHOMEEN” and available from Akzo Nobel. Representative examples ofthese ETHOMEEN™ materials is ETHOMEEN™ C/12(bis[2-hydroxyethyl]-cocoamine); ETHOMEEN™ C/20(polyoxyethylene[10]cocoamine); ETHOMEEN™ S/12(bis[2-hydroxyethyl]soyamine); ETHOMEEN™ T/12(bis[2-hydroxyethyl]allow-amine); ETHOMEEN™ T/15(polyoxyethylene-[5]tallowamine); ETHOMEEN™ 0/12(bis[2-hydroxyethyl]oleyl-amine); ETHOMEEN™ 18/12(bis[2-hydroxyethyl]octadecylamine); and ETHOMEEN™ 18/25(polyoxyethylene[15]octadecylamine). Fatty amines and ethoxylated fattyamines are also described in U.S. Pat. No. 4,741,848.

In one embodiment the other friction modifier may be a reaction productof an isomerised alkenyl substituted succinic anhydride and a polyamineas described in U.S. Pat. No. 5,840,663 in column 2, lines 18 to 43.Specific embodiments of the friction modifier described in U.S. Pat. No.5,840,663 are further disclosed in column 3, line 23 to column 4, line35. Preparative examples are further disclosed in column 4, line 45 tocolumn 5, line 37 of U.S. Pat. No. 5,840,663.

In one embodiment the other friction modifier may be an alkylphosphonatemono- or di-ester sold commercially by Rhodia under the trademarkDuraphos® DMODP.

In one embodiment the other friction modifier other may be a boratedfatty epoxide, known from Canadian Patent No. 1,188,704. Theseoil-soluble boron-containing compositions are prepared by reacting, at atemperature from 80° C. to 250° C., boric acid or boron trioxide with atleast one fatty epoxide. The fatty epoxide typically contains at least 8carbon atoms in the fatty groups of the epoxide.

The borated fatty epoxides may be characterised by the method for theirpreparation which involves the reaction of two materials. Reagent A maybe boron trioxide or any of the various forms of boric acid includingmetaboric acid (HBO₂), orthoboric acid (H₃BO₃) and tetraboric acid(H₂B₄O₇). Boric acid, and especially orthoboric acid. Reagent B may beat least one fatty epoxide. The molar ratio of reagent A to reagent B isgenerally 1:0.25 to 1:4, or 1:1 to 1:3, or about 1:2. The borated fattyepoxides may be prepared by merely blending the two reagents and heatingthem at temperature of 80° to 250° C., or 100° to 200° C., for a periodof time sufficient for reaction to take place. If desired, the reactionmay be effected in the presence of a substantially inert, normallyliquid organic diluent. During the reaction, water is evolved and may beremoved by distillation.

Friction Stabilising Agents

In one embodiment the lubricating composition further comprises afriction stabilising agent. Friction stabilising agents include H₃PO₄,H₃PO₃ or mixtures thereof. Typically H₃PO₄ is commercially available in85% solution.

Dispersant

In one embodiment the additive concentrate further comprises adispersant. The dispersant may be a succinimide dispersant (for exampleN-substituted long chain alkenyl succinimides), a Mannich dispersant, anester-containing dispersant, a condensation product of a fattyhydrocarbyl monocarboxylic acylating agent with an amine or ammonia, analkyl amino phenol dispersant, a hydrocarbyl-amine dispersant, apolyether dispersant or a polyetheramine dispersant.

In different embodiments the dispersant may be a succinimide, succinicacid ester, or Mannich dispersant.

In several embodiments the N-substituted long chain alkenyl succinimidescontain an average of at least 8, or 30, or 35 up to 350, or to 200, orto 100 carbon atoms. In one embodiment, the long chain alkenyl group isderived from a polyalkene characterised by an M _(n) (number averagemolecular weight) of at least 500. Generally, the polyalkene ischaracterised by an M _(n) of 500, or 700, or 800, or even 900 up to5000, or to 2500, or to 2000, or even to 1500 or 1200. In one embodimentthe long chain alkenyl group is derived form polyolefins. Thepolyolefins may be derived from monomers including monoolefins having 2to 10 carbon atoms such as ethylene, propylene, 1-butene, isobutylene,and 1-decene. An especially useful monoolefin source is a C₄ refinerystream having a 35 to 75 weight percent butene content and a 30 toweight percent isobutene content. Useful polyolefins includepolyisobutylenes having a number average molecular weight of 400 to5000, in another instance of 400 to 2500, and in a further instance of400 or 500 to 1500. The polyisobutylene may have a vinylidene doublebond content of 5 to 69%, in a second instance of 50 to 69%, and in athird instance of 50 to 95%.

In one embodiment the succinimide dispersant comprises apolyisobutylene-substituted succinimide, wherein thepolyisobutylene-substituent has a number average molecular weight of 400to 5000.

Succinimide dispersants and their methods of preparation are more fullydescribed in U.S. Pat. Nos. 4,234,435 and 3,172,892. The succinimidedispersant may also be prepared by either direct alkylation orchlorine-route.

Suitable ester-containing dispersants are typically high molecularweight esters. These materials are described in more detail in U.S. Pat.No. 3,381,022.

Mannich dispersants are the reaction product of ahydrocarbyl-substituted phenol, an aldehyde, and an amine or ammonia.The hydrocarbyl substituent of the hydrocarbyl-substituted phenol mayhave 10 to 400 carbon atoms, in another instance 30 to 180 carbon atoms,and in a further instance 10 or 40 to 110 carbon atoms. This hydrocarbylsubstituent may be derived from an olefin or a polyolefin. Usefulolefins include alpha-olefins, such as 1-decene, which are commerciallyavailable.

Hydrocarbyl-amine dispersants are hydrocarbyl-substituted amines. Thehydrocarbyl-substituted amine may be formed by heating a mixture of achlorinated olefin or polyolefin such as a chlorinated polyisobutylenewith an amine such as ethylenediamine in the presence of a base such assodium carbonate as described in U.S. Pat. No. 5,407,453.

Polyether dispersants include polyetheramines, polyether amides,polyether carbamates, and polyether alcohols. Polyetheramines and theirmethods of preparation are described in greater detail in U.S. Pat. No.6,458,172, columns 4 and 5.

In one embodiment the invention further comprises at least onedispersant derived from polyisobutylene, an amine and zinc oxide to forma polyisobutylene succinimide complex with zinc. The polyisobutylenesuccinimide complex with zinc may be used alone or in combination.

The dispersants may also be post-treated by conventional methods by areaction with any of a variety of agents. Among these are boron, urea,thiourea, dimercaptothiadiazoles, carbon disulphide, aldehydes, ketones,carboxylic acids, hydrocarbon-substituted succinic anhydrides, maleicanhydride, nitriles, epoxides, phosphorus compounds and/or metalcompounds. In one embodiment the dispersant is a borated dispersant.Typically the borated dispersant comprises a succinimide dispersantwhich in turn comprises a polyisobutylene succinimide, wherein thepolyisobutylene has a number average molecular weight of 400 to 5000.

In one embodiment the dispersant is phosphorylated dispersant, or aborated phosphorylated dispersant.

In one embodiment the dispersant may be prepared by heating (i) adispersant material described above (for example N-substituted longchain alkenyl succinimides), (ii) 2,5-dimercapto-1,3,4-thiadiazole or ahydrocarbyl-substituted 2,5-dimercapto-1,3,4-thiadiazole, or oligomersthereof, (iii) a borating agent, and (iv) optionally a dicarboxylic acidof an aromatic compound selected from the group consisting of 1,3diacids and 1,4 diacids; or (v) optionally a phosphorus acid compound,said heating being sufficient to provide a product of (i), (ii), (iii)and optionally (iv) or (v), which is soluble in an oil of lubricatingviscosity. The dispersant prepared by heating is described in moredetail in US Patent Applications US04/027094 and 60/654,164 (now WO2006/091387).

Antioxidants

In one embodiment the lubricating composition further comprises anantioxidant. The antioxidant may be present in ranges of 0 wt % to 10 wt%, 0.01 wt % to 5 wt %, or 0.05 wt % to 3 wt % of the lubricatingcomposition.

Suitable antioxidants include molybdenum compounds such as molybdenumdithiocarbamates, sulphurised olefins, sulphides (includinghydroxylalkyl sulphides such as 1-(tert-dodecylthio)-2-propanol ortert-nonyl mercaptan reacted with propylene oxide (mole ratio 1:1)),hindered phenols including ester-substituted hindered phenols, aminiccompounds such as phenylalphanaphthylamines or alkylated diphenylamines(typically nonyl diphenylamine, di-nonyl diphenylamine, octyldiphenylamine, di-octyl diphenylamine), or mixtures thereof.

Viscosity Modifiers

In one embodiment the lubricating composition further comprises aviscosity modifier or dispersant viscosity modifier (also referred to asDVMs). The viscosity modifier may be present at 0 wt % to 12 wt %, 0.1wt % to 10 wt % or 1 wt % to 8 wt % of the lubricating composition.

Viscosity modifiers include hydrogenated copolymers ofstyrene-butadiene, ethylene-propylene copolymers, polyisobutenes,hydrogenated styrene-isoprene polymers, hydrogenated isoprene polymers,polymath-acrylates, polyacrylates, polyalkyl styrenes, alkenyl arylconjugated diene copolymers, polyolefins, and esters of maleicanhydride-styrene copolymers.

Dispersant viscosity modifiers include functionalised polyolefins, forexample, ethylene-propylene copolymers that have been functionalizedwith the reaction product of maleic anhydride and an amine, apolymethacrylate functionalised with an amine, or styrene-maleicanhydride copolymers reacted with an amine; may also be used in thecomposition of the invention.

Detergents

In one embodiment the lubricating composition further comprises adetergent Detergents include neutral or overbased detergents, Newtonianor non-Newtonian, basic salts of alkali, alkaline earth or transitionmetals with one or more of a phenate, a sulphurised phenate, asulphonate, a carboxylic acid, a phosphorus acid, a saligenin, analkylsalicylate, and a salixarate. The alkali metal includes sodium. Thealkaline earth metal may be calcium, magnesium or barium. In differentembodiments the detergent may be a magnesium sulphonate or a calciumsulphonate.

Other optional components include foam inhibitors, includingpolydimethyl siloxane, fluorosilicone, copolymers of ethyl acrylate and2-ethylhexylacrylate and optionally vinyl acetate; demulsifiersincluding trialkyl phosphates, polyethylene glycols, polyethyleneoxides, polypropylene oxides and (ethylene oxide-propylene oxide)polymers; pour point depressants including esters of maleicanhydride-styrene, polymethacrylates, polyacrylates or polyacrylamides.

Seal swell agents including 3-(decyloxy)tetrahydro-1,1-dioxidethiophene, decyloxysulpholane, phthalate esters, Exxon Necton37™ (FN1380) and Exxon Mineral Seal Oil (FN 3200) may also be present in thelubricating composition.

INDUSTRIAL APPLICATION

The method of the invention is useful for lubricating a variety oftransmissions including an automatic transmission or a manualtransmission. In one embodiment the mechanical device is an automatictransmission.

The automatic transmission includes continuously variable transmissions(CVT), infinitely variable transmissions (IVT), Toroidal transmissions,continuously slipping torque converted clutches (CSTCC), steppedautomatic transmissions or dual clutch transmissions (DCT).

The following examples provide illustrations of the invention. Theseexamples are non-exhaustive and are not intended to limit the scope ofthe invention.

EXAMPLES

A conventional automatic transmission fluid is evaluated for frictionand squawk performance using a test methodology as defined below. Theconventional automatic transmission fluid is evaluated as (i) a newfluid, (ii) a new fluid that is aged at 150° C. for 100 hours, and (iii)the aged fluid of (ii) is then aged for 100 hours at 150° C. Fluid (iii)has therefore been aged for a total of 200 hours at 150° C.

The automatic transmission fluid is evaluated in a ZF®-GK rig firstutilising standard methods to evaluate frictional performance, and thenfurther evaluated for squawk performance using the procedure set forthin ZF test procedure “PVL44_Quietschversuche_(—)6HP26E_V2.0.pv”. Theprocedure “PVL44_Quietschversuche_(—)6HP26E_V2.0.pv” is available fromZF Passau GmbH, Test Systems, Tittlinger Strasse 28, D-94034 Passau,Germany. In order to obtain squawk performance data the GK-rig employedis configured by addition of ZF Squawk Modifications, including theaddition of a data acquisition recorder capable of recording squawk. Theresults obtained are:

Test Test Procedure Test Fluid Parameter(limit) Test Result GWK FrictionATF with 12 wt Slope (increase Increasing Test % of the top treat withspeed) additive μ5 (0.110 to 0.109 concentrate of the 0.113) inventionadded GK E Clutch torque Squawk Test oscillation <50 Nm at p ≦ 1.625N/mm² 100 Hrs before ATF fluid with no Fail, >50 Nm run in top treatadditive at 0.9 N/mm² concentrate 100 Hrs after ATF fluid with noFail, >50 Nm run in top treat additive at 0.75 N/mm² concentrate 200 HrsATF fluid with no Fail, >50 Nm additional aging top treat additive at0.5 N/mm² at 150° C. concentrate Before running ATF with 12 wt Pass, noin % of the top treat oscillation >50 additive Nm concentrate of theinvention added After running in ATF with 12 wt Pass, no % of the toptreat oscillation >50 additive Nm concentrate of the invention added 100Hrs ATF with 12 wt Pass, no additional aging % of the top treatoscillation >50 at 150° C. additive Nm concentrate of the inventionadded

Overall the data indicates that the automatic transmission fluid treatedwith the additive concentrate as a top treat package is capable ofminimising noise, shudder, chattering, or squawking, whilst also notadversely affecting the frictional balance and clutch holding capacity,nor increasing lubricant waste. This allows for the transmission tooperate with appropriate frictional performance and minimised noise,shudder, chatter or squawk.

As used herein, the term “hydrocarbyl substituent” or “hydrocarbylgroup” is used in its ordinary sense, which is well-known to thoseskilled in the art. Specifically, it refers to a group having a carbonatom directly attached to the remainder of the molecule and havingpredominantly hydrocarbon character. Examples of hydrocarbyl groupsinclude:

-   -   (i) hydrocarbon substituents, that is, aliphatic (e.g., alkyl or        alkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl)        substituents, and aromatic-, aliphatic-, and        alicyclic-substituted aromatic substituents, as well as cyclic        substituents wherein the ring is completed through another        portion of the molecule (e.g., two substituents together form a        ring);    -   (ii) substituted hydrocarbon substituents, that is, substituents        containing non-hydrocarbon groups which, in the context of this        invention, do not alter the predominantly hydrocarbon nature of        the substituent (e.g., halo (especially chloro and fluoro),        hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso, and        sulphoxy);    -   (iii) hetero substituents, that is, substituents which, while        having a predominantly hydrocarbon character, in the context of        this invention, contain other than carbon in a ring or chain        otherwise composed of carbon atoms, and encompass substituents        as pyridyl, furyl, thienyl and imidazolyl. Heteroatoms include        sulphur, oxygen, nitrogen. In general, no more than two,        preferably no more than one, non-hydrocarbon substituent will be        present for every ten carbon atoms in the hydrocarbyl group;        typically, there will be no non-hydrocarbon substituents in the        hydrocarbyl group.

It is known that some of the materials described above may interact inthe final formulation, so that the components of the final formulationmay be different from those that are initially added. The productsformed thereby, including the products formed upon employing lubricantcomposition of the present invention in its intended use, may not besusceptible of easy description. Nevertheless, all such modificationsand reaction products are included within the scope of the presentinvention; the present invention encompasses lubricant compositionprepared by admixing the components described above.

Each of the documents referred to above is incorporated herein byreference. Except in the Examples, or where otherwise explicitlyindicated, all numerical quantities in this description specifyingamounts of materials, reaction conditions, molecular weights, number ofcarbon atoms, and the like, are to be understood as modified by the word“about.” Unless otherwise indicated, each chemical or compositionreferred to herein should be interpreted as being a commercial gradematerial which may contain the isomers, by-products, derivatives, andother such materials which are normally understood to be present in thecommercial grade. However, the amount of each chemical component ispresented exclusive of any solvent or diluent oil, which may becustomarily present in the commercial material, unless otherwiseindicated. It is to be understood that the upper and lower amount,range, and ratio limits set forth herein may be independently combined.Similarly, the ranges and amounts for each element of the invention maybe used together with ranges or amounts for any of the other elements.

While the invention has been explained in relation to its preferredembodiments, it is to be understood that various modifications thereofwill become apparent to those skilled in the art upon reading thespecification. Therefore, it is to be understood that the inventiondisclosed herein is intended to cover such modifications as fall withinthe scope of the appended claims.

1. A method of lubricating a transmission by supplying to the transmission a lubricating composition further treated with an additive concentrate comprising: (a) 4 wt % to 67 wt % of a static friction reducing friction modifier; (b) 0.1 wt % to 5 wt % of a corrosion inhibitor; (c) 3 wt % to 96 wt % of an oil of lubricating viscosity; and (d) 0 wt % to 20 wt % of other performance additives, wherein the static friction reducing friction modifier is an amide represented by the formula R¹R²N—C(O)R³, wherein R¹ and R² are each independently hydrocarbyl groups of at least 6 carbon atoms and R³ is a hydroxyalkyl group of 1 to 6 carbon atoms or a group formed by the condensation of said hydroxyalkyl group, through a hydroxyl group thereof, with an acylating agent.
 2. The method of claim 1, wherein the additive concentrate contains the static friction reducing friction modifier at 10 wt % to 50 wt %.
 3. The method of claim 1, wherein the additive concentrate contains the static friction reducing friction modifier at 20 wt % to 40 wt %.
 4. The method of claim 1, wherein the additive concentrate contains the corrosion inhibitor at 0.2 wt % to 3 wt %.
 5. The method of claim 1, wherein the additive concentrate is supplied to the transmission as a service-fill top treat.
 6. The method of claim 1, wherein the additive concentrate is supplied to the transmission as a service-fill top treat at 0.1 wt % to 30 wt %.
 7. The method of claim 1, wherein the additive concentrate is supplied to the transmission as a service-fill top treat at 1 wt % to 15 wt %.
 8. A method of lubricating a transmission containing a lubricant comprising supplying to the lubricant within the transmission an additive concentrate comprising: (a) 4 wt % to 67 wt % of a static friction reducing friction modifier; (b) 0.1 wt % to 5 wt % of a corrosion inhibitor; (c) 3 wt % to 96 wt % of an oil of lubricating viscosity; and (d) 0 wt % to 20 wt % of other performance additives, wherein the static friction reducing friction modifier is an amide represented by the formula R¹R²N—C(O)R³, wherein R¹ and R² are each independently hydrocarbyl groups of at least 6 carbon atoms and R³ is a hydroxyalkyl group of 1 to 6 carbon atoms or a group formed by the condensation of said hydroxyalkyl group, through a hydroxyl group thereof, with an acylating agent.
 9. An additive concentrate comprising: (a) 4 wt % to 67 wt % of a static friction reducing friction modifier; (b) 0.1 wt % to 5 wt % of a corrosion inhibitor; (c) 3 wt % to 96 wt % of an oil of lubricating viscosity; and (d) 0 wt % to 20 wt % of other performance additives, wherein the static friction reducing friction modifier is an amide represented by the formula R¹R²N—C(O)R³, wherein R¹ and R² are each independently hydrocarbyl groups of at least 6 carbon atoms and R³ is a hydroxyalkyl group of 1 to 6 carbon atoms or a group formed by the condensation of said hydroxyalkyl group, through a hydroxyl group thereof, with an acylating agent.
 10. A method of lubricating a transmission by supplying to the transmission a lubricating composition further treated with an additive concentrate comprising: (a) 4 wt % to 67 wt % of a static friction reducing friction modifier; (b) 0.1 wt % to 5 wt % of a corrosion inhibitor; (c) 3 wt % to 96 wt % of an oil of lubricating viscosity; and (d) 0 wt % to 20 wt % of other performance additives, wherein the static friction reducing modifier comprises a tertiary amine, wherein the amine contains three substituent hydrocarbyl groups, two of which are alkyl groups, and the amine is represented by the formula: R⁴R⁵NR⁶ wherein R⁴ and R⁵ are each independently an alkyl group of at least 6 carbon atoms and R⁶ is a polyhydroxyl-containing alkyl group or a polyhydroxyl-containing alkoxyalkyl group.
 11. A method of lubricating a transmission by supplying to the transmission a lubricating composition further treated with an additive concentrate comprising: (a) 4 wt % to 67 wt % of a static friction reducing friction modifier; (b) 0.1 wt % to 5 wt % of a corrosion inhibitor; (c) 3 wt % to 96 wt % of an oil of lubricating viscosity; and (d) 0 wt % to 20 wt % of other performance additives, wherein the static friction reducing modifier comprises an amine, wherein the amine is secondary or tertiary amine being represented by the formula: R⁷R⁸NR⁹ wherein R⁷ and R⁸ are each independently an alkyl group of at least 6 carbon atoms and R⁹ is a hydroxyl-containing alkyl group, a hydroxyl-containing alkoxyalkyl group, an amine-containing alkyl group, a hydrocarbyl group, or hydrogen, provided that when R⁹ is H, then at least one of R⁷ and R⁸ is an alkyl group of 8 to 16 carbon atoms. 